G0678 CNC Conversion Build Log

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Harold_V
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Re: G0678 CNC Conversion Build Log

Post by Harold_V »

Thanks, Dave. You sure do pretty work. :wink:

H
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GlennW
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Re: G0678 CNC Conversion Build Log

Post by GlennW »

That's a REALLY nice conversion that you have done!

I switched to using form taps for anything 1/4" and smaller.

No swarf to pack the flutes and plug up the bottom of the hole causing tap breakage.

Different tap drill sizes needed, and Moly Dee tapping fluid is the way to go, but other than that, I just push the big green button and don't even think about a tap breaking.
Glenn

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Harold_V
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Re: G0678 CNC Conversion Build Log

Post by Harold_V »

GlennW wrote: Thu May 31, 2018 8:46 pm I switched to using form taps for anything 1/4" and smaller.
I had to tap a large number of holes when I built the switch plates for the low voltage control light system for our house. I decided the form taps would be a great choice. While I made the plates with my Haas, I tapped the holes afterwards, using a Procunier tapping head. I really enjoyed not having to deal with chips, and could tap to full depth without issue. A great way to generate threads.

I've never tried tapping with my CNC--although I do have a couple of tapping adapters and collets. It's not equipped with rigid tapping. Maybe someday---when need arises.

H
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Dave_C
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Re: G0678 CNC Conversion Build Log

Post by Dave_C »

I got the chip guard finished! It works pretty well and it just lifts out of the 1/4" channel when I need to make a tool change. I may at some point add a back splash didn't spray to far to the rear so maybe I'll just go with it as it is.

I made a 4 1/2" table extension towards the front of the table out of .080" aluminum and bolted the channels to the plate. The 4 1/2" is just enough that the end of the mill vise fits inside the guard but still allows me to get the vise handle on to clamp parts. It keep the chips out from under my feet and off the front of the mill ways.

It's not obvious but to insert the vise hold down bolts I have to remove two #6 screws and then the end channel comes off. Easy to do but kind of a pain so I just leave the bolts in the slots now since I have more than one set of vise bolts!

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0522181312 (2).jpg
Dave C.
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GlennW
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Re: G0678 CNC Conversion Build Log

Post by GlennW »

Someone added a folded sheet metal tray with a drain to mine of similar dimensions to your extension.

The table was made with drains as is my Bridgeport table.

Certainly nowhere near as nice as yours, but it works very well at catching the coolant.
DSC01018.JPG
Glenn

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remcb
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Re: G0678 CNC Conversion Build Log

Post by remcb »

Dave_C wrote: Fri Jun 01, 2018 12:34 pm I got the chip guard finished! It works pretty well and it just lifts out of the 1/4" channel when I need to make a tool change. I may at some point add a back splash didn't spray to far to the rear so maybe I'll just go with it as it is.

I made a 4 1/2" table extension towards the front of the table out of .080" aluminum and bolted the channels to the plate. The 4 1/2" is just enough that the end of the mill vise fits inside the guard but still allows me to get the vise handle on to clamp parts. It keep the chips out from under my feet and off the front of the mill ways.

It's not obvious but to insert the vise hold down bolts I have to remove two #6 screws and then the end channel comes off. Easy to do but kind of a pain so I just leave the bolts in the slots now since I have more than one set of vise bolts!


0522181311 (2).jpg

0522181312 (2).jpg

Dave C.
Dave— I’ve followed your G0678 conversion project both on you tube and on the home machinists site. I’m about to start this project on my soon to be delivered G0678. I’m request your assistance by sharing any detail info. not included in you post. Such as sources for such things as motor mounts, trimming belts and pulleys, ball screws and nuts, etc. Any shop drawings or sketches you would be willing to share—if they still exist. My plan is to try to fabricate all the needed machine components using the G0678 before I disassemble it. I know some machine part will need to be modified so if take them to the local University and use there equipment for those modifications. Any help or suggestions would be greatly appreciated. Ron McB
TimFromPhx
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Re: G0678 CNC Conversion Build Log

Post by TimFromPhx »

Dave,

I am currently doing a CNC conversion on a machine that is the predecessor to your grizzly G0678. In your wonderful build documentation you showed that you were driving the Z-axis using a stepper motor to control the spindle geared manual feed. You mentioned that you might lock the spindle in place and drive the knee up and down instead. I am wondering how accurate that geared feed was for the Z-axis? Can you tell me approximately what kind of tolerance you can hold with that set up? Would you recommend that I drive the whole knee up and down instead? It seems like that would be moving quite a bit of mass to do things like drill holes. Do you have a recommendation?
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Harold_V
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Re: G0678 CNC Conversion Build Log

Post by Harold_V »

Please note that Dave has gone silent as of March of last year. He most likely won't respond to your question.

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Wise people talk because they have something to say. Fools talk because they have to say something.
TimFromPhx
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Re: G0678 CNC Conversion Build Log

Post by TimFromPhx »

Thanks for your reply Harold,

I was wondering if he would still be around. I guess I will go ahead and use the up-and-down motion of the spindle as the Z-axis.
joedexter
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Re: G0678 CNC Conversion Build Log

Post by joedexter »

I have a G 0678 that I am going to convert to cnc, and have read the posts by various contributors. Does anyone have a build sequence they used? And does anyone have a parts list that was used?
I am inclined towards Acorn, closed loop hybrid and using the knee for Z axis drive.
I have a second mill so I’m not limited to parts fabrication.
Thank you.
J
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Bill Shields
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Re: G0678 CNC Conversion Build Log

Post by Bill Shields »

First you need ball screws. Does grizzly sell them?

Knee for Z would not be my choice.
Too many things going on to bother listing them.
joedexter
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Re: G0678 CNC Conversion Build Log

Post by joedexter »

Thanks Bill
There is quite a choice of ball screws beyond Grizzly, who appear to be quite expensive. Ex-China cut to length for C7, priced well with 14 day delivery.
Using a drive on the knee for Z does look challenging, notably both knee and quill has been used. I’m ambivalent.
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